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Majorica
Majorica is a Spanish company that manufactures hand-made pearls called Majorica pearls. Now based in Majorca, the company was founded in 1890 in Barcelona. In 1990, ''Gems & Gemology'' described Majorica pearls as "the most widely marketed and meticulously manufactured imitation [pearl] today". Production Majorica imitation pearls are man-made on solid balls, likely made of glass, that are coated with a proprietary coating that is made in part from fish scales. The coated nuclei are then dried and polished, and then dipped in a chemical (possibly cellulose acetate and Nitrocellulose, cellulose nitrate) to harden the surface and guard against discoloration, chipping, and peeling. References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gems & Gemology
''Gems & Gemology'' is a quarterly scientific journal published by the Gemological Institute of America. Each issue is devoted to research on diamonds, gemstones, and pearls. Topics include geographic sources, imitations and synthetics, treatments, and identification techniques. Established in January 1934, ''Gems & Gemology'' is geared toward jewelry professionals and gemologists. Issues contain research articles, updates from the GIA Laboratory and international gemology news. ''Gems & Gemology'' is abstracted and indexed by the Science Citation Index. According to the ''Journal Citation Reports'', its 2016 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... is 0.793, ranking it 24th out of 29 journals in the category "Mineralogy". References External links * Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Majorca
Mallorca, or Majorca, is the largest of the Balearic Islands, which are part of Spain, and the List of islands in the Mediterranean#By area, seventh largest island in the Mediterranean Sea. The capital of the island, Palma, Majorca, Palma, is also the capital of the autonomous communities of Spain, autonomous community of the Balearic Islands. The Balearic Islands have been an autonomous region of Spain since 1983. There are two small islands off the coast of Mallorca: Cabrera, Balearic Islands, Cabrera (southeast of Palma) and Dragonera (west of Palma). The anthem of Mallorca is "La Balanguera". Like the other Balearic Islands of Menorca, Ibiza, and Formentera, the island is a highly popular holiday destination, particularly for tourists from the Netherlands, Republic of Ireland, Ireland, Germany, and the United Kingdom. The international airport, Palma de Mallorca Airport, is one of the busiest in Spain; it was used by 28 million passengers in 2017, with use increasing ever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barcelona
Barcelona ( ; ; ) is a city on the northeastern coast of Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second-most populous municipality of Spain. With a population of 1.6 million within city limits,Barcelona: Población por municipios y sexo – Instituto Nacional de Estadística. (National Statistics Institute) its urban area extends to numerous neighbouring municipalities within the province of Barcelona and is home to around 5.3 million people, making it the fifth most populous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose Acetate
In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and as a frame material for eyeglasses; it is also used as a synthetic fiber in the manufacture of Cigarette filter, cigarette filters and Playing card, playing cards. In cellulose acetate film, photographic film, cellulose acetate film replaced nitrate film in the 1950s, being far less flammable and cheaper to produce. Water-soluble cellulose acetate (WSCA) has been used as a Prebiotic (nutrition), dietary fiber (prebiotic), in relation with weight loss and Akkermansia muciniphila. History In 1865, French chemist Paul Schützenberger discovered that cellulose reacts with acetic anhydride to form cellulose acetate. The German chemists Arthur Eichengrün and Theodore Becker invented the first soluble forms of cellulose acetate in 1903. In 190 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrocellulose
Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and sulfuric acid. One of its first major uses was as guncotton, a replacement for gunpowder as propellant in firearms. It was also used to replace gunpowder as a low-order explosive in mining and other applications. In the form of collodion, it was also a critical component in an early photographic emulsion, the use of which revolutionized photography in the 1860s. In the 20th century, it was adapted to automobile lacquer and adhesives. Production The process uses a mixture of nitric acid and sulfuric acid to convert cellulose into nitrocellulose. The quality of the cellulose is important. Hemicellulose, lignin, pentosans, and mineral salts give inferior nitrocelluloses. In organic chemistry, nitrocellulose is a nitrate ester, not a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pearls
A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle (mollusc), mantle) of a living Exoskeleton, shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carbonate (mainly aragonite or a mixture of aragonite and calcite) in minute crystalline form, which has deposited in concentric layers. More commercially valuable pearls are perfectly round and smooth, but many other shapes, known as baroque pearls, can occur. The finest quality of natural pearls have been highly valued as gemstones and objects of beauty for many centuries. Because of this, ''pearl'' has become a metaphor for something rare, fine, admirable, and valuable. The most valuable pearls occur spontaneously in the wild but are extremely rare. These wild pearls are referred to as ''natural'' pearls. ''Cultured'' or ''farmed'' pearls from Pinctada, pearl oysters and freshwater mussels make up the majority o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
